Explosives or blasting compositions of the aqueous gel or slurry type, commonly referred to as slurry explosives or blasting agents, and referred to herein as aqueous blasting compositions, have achieved wide acceptance as commercial blasting agents owing to their low cost, safety and inherent water-resistance. Aqueous blasting compositions, containing a continuous liquid phase and comprising generally an inorganic oxidizing salt (usually predominantly ammonium nitrate (AN)), a thickening agent for the liquid phase in which some or all of the oxidizing salt is dissolved, a fuel and/or sensitizer and, optionally, other ingredients such as gassing and cross-linking agents, have been very successful even in water-containing boreholes.
An application where aqueous blasting compositions have not yet received widespread use is in the permissible explosive field. Generally, permissible explosives are those which are cap sensitive and which are relatively nonincendive so they can be used in underground mines having potentially flammable atmospheres, such as underground coal mines. Specifically, the United States Department of Labor Mine Safety and Health Administration has established detailed requirements for approval of permissible explosives for underground use. These requirements are published in 30 C.F.R. Part 15. These regulations, which are incorporated herein by reference, define permissible explosives in terms of minimum requirements, which are summarized in Table I below.